Tickets for Apple's developer conference sold out on the day they went on sale this week. However rumors suggest that there won't be any hardware unveiled at the event - and that means no new iPhone.

Apple's annual Worldwide Developers Conference (WWDC) take place from June 6-10 at its usual venue, Moscone West in San Francisco. Tickets for the 5-day event cost $1559 and although Apple didn't officially announced that the event sold out, it placed a graphic on its website stating the fact and removed all links to the checkout page for the event. The number of tickets sold and what limits there are the total number of attendees have not been disclosed and that Apple could make some extra tickets available - as Google did for its sell-out conference.

Given that last year's event sold out in a (then record) 8 days and this year's in a little over 8 hours there is obvious enthusiasm among developers for Apple's platforms - but mobile developers may feel short-changed. In previous years Apple has announced the new version of iPhone hardware at WWDC - iPhone 3G in 2008, 3GS in 2009 and iPhone 4 in 2010 but it is rumored that there won't be an iPhone 5 at the 2011 event and that Apple won't release iOS 5 until the autumn.

According to Apple will focus on "the future of iOS and Mac OS" and there is speculation that the show will feature a Golden Master of OS X Lion.